Viewing archive of Sunday, 16 March 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Mar 16 1231 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
16 Mar 2025	185	013
17 Mar 2025	185	015
18 Mar 2025	185	007

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. The largest flare was a C4.4 flare peaking on March 16 at 08:03 UTC, which was produced by SIDC Sunspot Group 428 (NOAA Active Region 4019). A total of 13 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 428 (NOAA Active Region 4019) has the most complex magnetic configuration (Beta-Gamma-Delta). Solar flaring activity is expected to be moderate over the next 24 hours, with C-class flares expected and M-class flares likely.

Coronal mass ejections

No new Earth-directed Coronal Mass Ejections (CMEs) have been detected in the available coronagraph images.

Solar wind

The solar wind at the Earth transitioned from fast to slow, with speeds gradually decreasing from 560 to 440 km/s and interplanetary magnetic field around 5 nT, with the Bz reaching a minimum value of -5 nT. In the next 24h, the solar wind speed may increase due to the influence of the high-speed stream associated with the coronal hole which reached the central meridian March 13.

Geomagnetism

In the past 24 hours, geomagnetic conditions were mainly quiet to unsettled (Kp3) with an isolated active period at noon March 15. Geomagnetic conditions are expected tor each active levels in the next 24 hours, due to a the high speed stream arrival.

Proton flux levels

The greater than 10 MeV proton flux remained below the 10 pfu threshold and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux exceeded the 1000 pfu threshold for most of the time during the past 24 hours, and is expected to remain above the threshold during the next 24 hours. The 24h electron fluence was at normal levels and is expected to remain so.

Today's estimated international sunspot number (ISN): 210, based on 13 stations.

Solar indices for 15 Mar 2025

Wolf number Catania	///
10cm solar flux	178
AK Chambon La Forêt	016
AK Wingst	014
Estimated Ap	015
Estimated international sunspot number	166 - Based on 16 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

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